preflight

A reusable starter kit of AI-agent standards, personas, and workflows for new projects, distributed as a Claude Code plugin. Install it once, then run /preflight:setup in any repo to stamp local, editable copies into that repo's .claude/. It is a scaffold, not a live dependency — once scaffolded, each project owns and edits its own copies, and plugin updates never touch them.

What it installs into a project

Everything is branched so it loads only when it is relevant, keeping context lean:

Loaded	What	Where it lands
Always-on	working-style — propose-before-implementing, a question isn't a work order, report honestly, flag reusable logic, scope discipline & the simplest solution	.claude/standards/, imported by CLAUDE.md
When editing *.py	python — 3.13+, type hints, PEP 695, uv, structured logging, definition ordering, suppression discipline, async safety	.claude/rules/
When editing *.py (opt-in)	scalable-architecture — ports-and-adapters, dependency injection, boundary validation, idempotent writes; patterns for services/larger apps	.claude/rules/
When editing *.md	prose-and-docs — no historical narration, verify before documenting, voice, ordering, RFC-2119 & leanness	.claude/rules/
When committing	git-conventions skill — branches, explicit staging, current-behaviour messages, co-author trailer	.claude/skills/
When spawning subagents	subagent-orchestration skill — model/effort defaults, MCP tool-cost discipline, delegation	.claude/skills/
Personas	technical-writer, lean-implementer, janitor, web-researcher	.claude/agents/

The root CLAUDE.md stays a thin index; the depth lives in the files above and loads on demand.

Install

/plugin marketplace add assert-not-singularity/preflight
/plugin install preflight@preflight

Use

In a new (or existing) repo:

/preflight:setup

It detects repo signals (Python? git?), presents grouped checkboxes (Personas / Standards & rules / Workflows) so you install only what the repo needs, copies the selected templates in without overwriting anything you have customised, wires the always-on standard into CLAUDE.md, and asks for the one-line project purpose. It records your selection and a pristine base snapshot so updates can merge cleanly later (see below).

Edit & update

• Edit freely. The scaffolded files are yours — change any persona, rule, or standard per project and commit it. Project-level files override anything with the same name.
• Roll kit changes into an edited project. Run /plugin marketplace update to fetch the new templates, then /preflight:update in the project. It does a three-way merge — ancestor (.claude/.preflight-base/) vs. new template vs. your edited file — applying upstream improvements while preserving your changes, and asking you to confirm any genuine conflict. It also offers newly added components as checkboxes. Your edits are never silently discarded.
• Improve the kit. Edit the templates under plugin/templates/, bump the version in plugin/.claude-plugin/plugin.json, and push.

How a project remembers the kit

/preflight:setup writes two things into the project so /preflight:update can merge intelligently:

• .claude/.preflight.json — the version scaffolded and which components are installed.
• .claude/.preflight-base/ — pristine copies of the scaffolded files, the merge ancestor.

Commit both. Without them /preflight:update can only offer a 2-way diff-and-choose, not a real merge.

Layout

preflight/
├─ .claude-plugin/marketplace.json     # this repo is a plugin marketplace
├─ plugin/
│  ├─ .claude-plugin/plugin.json       # the "preflight" plugin manifest
│  ├─ components.json                  # menu of scaffoldable components (shared by both commands)
│  ├─ commands/
│  │  ├─ setup.md                      # interactive scaffold: pick components → copy into a project
│  │  └─ update.md                     # 3-way merge new templates into an edited project
│  └─ templates/                       # copied into a project's .claude/ by /preflight:setup
│     ├─ agents/                        # personas
│     ├─ rules/                         # file-scoped (paths: globs)
│     ├─ skills/                        # task-triggered
│     ├─ standards/working-style.md     # always-on
│     └─ CLAUDE.md                      # thin project index skeleton
└─ README.md